WO2017017916A1

WO2017017916A1 - Temperature sensor

Info

Publication number: WO2017017916A1
Application number: PCT/JP2016/003272
Authority: WO
Inventors: 長友　憲昭; 文夫松本; 均稲葉; 一太竹島; 山口　邦生; 寛田中
Original assignee: 三菱マテリアル株式会社
Priority date: 2015-07-30
Filing date: 2016-07-11
Publication date: 2017-02-02
Also published as: US20180217007A1; JP2017032336A; JP6617909B2; CN107923801A

Abstract

A temperature sensor of the present invention is provided with a pair of lead frames 2, a sensor section 3 connected to the lead frames, and an insulating holding section 4 that holds the lead frames. The sensor section is provided with: an insulating film 5 having the lead frames bonded on the upper surface; a thin film thermistor section 6 formed on the insulating film; a pair of interdigital electrodes 7 formed on the thin film thermistor section; a pair of pattern electrodes formed on the upper surface of the insulating film; and a pair of protection tapes 9A, 9B, which are bonded to each other by vertically sandwiching therebetween the pair of lead frames and the sensor section. Both side sections 5a of the insulating film are disposed close to and on the inner sides of outer corner sections 2b that are disposed on the bonding surface sides of the pair of lead frames, and both side sections 9a of the protection tapes are bent on the outer side of both the side sections of the insulating film, said side sections 9a being bent toward the upper surface side.

Description

Temperature sensor

The present invention relates to a temperature sensor suitable for measuring the temperature of a heating roller of a copying machine, a printer or the like and having excellent responsiveness.

Generally, a heating sensor used in a copying machine or a printer is provided with a temperature sensor in contact with the heating roller in order to measure its temperature. As such a temperature sensor, for example, in Patent Document 1, a pair of lead frames, a thermal element disposed and connected between the lead frames, and a holding portion formed at an end portion of the pair of lead frames. And a temperature sensor having a protective tape (thin film sheet) that is provided on one side of the lead frame and the thermal element and is brought into contact with the heating roller.
In Patent Document 1, a thin film thermistor in which a heat sensitive film is formed on one surface of an insulating substrate such as alumina is employed in addition to a bead thermistor and a chip thermistor as a heat sensitive element.

In recent years, a temperature sensor in which a thin film thermistor is formed on an insulating film has been developed as a film-type temperature sensor that is excellent in flexibility and can be thinned as a whole. For example, Patent Document 2 discloses a temperature sensor including a pair of lead frames, a sensor unit connected to the pair of lead frames, and an insulating holding unit fixed to the pair of lead frames to hold the lead frame. Has been proposed.

In this temperature sensor, the sensor unit has an insulating film, a thin film thermistor portion patterned with the thermistor material on the surface of the insulating film, and a plurality of comb portions above and below the thin film thermistor portion. A pair of comb electrodes patterned to face each other, and a pair of pattern electrodes connected to the pair of comb electrodes and patterned on the surface of the insulating film. A thin film thermistor portion is extended and bonded to the surface of the film, and is connected to a pair of pattern electrodes.

JP 2000-74752 A JP 2014-52228 A

The following problems remain in the conventional technology.
In other words, in the technique described in Patent Document 1, when pressing against a measurement object such as a heating roller, the

protective tapes

9A and 9B having thin outer corners 2b of the pair of lead frames 2 are attached as shown in FIG. In other words, the measurement object such as a heating roller comes into contact with the edge, and there is a possibility that the measurement object may be damaged by the edge-shaped outer corner 2b. Note that reference numeral 101 in FIG. 5 denotes a chip thermistor.
Further, in the technique described in Patent Document 2, if the protective tape is adhered to the contact surface side of the insulating film and used as in the technique described in Patent Document 1, the gap between the lead frame and the protective tape is used. Although it is difficult for the object to be measured to be scratched due to the presence of the insulating film, the heat capacity and the contact area are increased by attaching a wider protective tape to the wide insulating film, and the responsiveness is lowered. There was a fear.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a temperature sensor that is less likely to be scratched and has good responsiveness when temperature measurement is performed by contacting the measurement object. And

The present invention employs the following configuration in order to solve the above problems. That is, the temperature sensor according to the first aspect of the invention includes a pair of lead frames, a sensor unit connected to the pair of lead frames, and an insulating property that is fixed to the pair of lead frames and holds the pair of lead frames. And a thin film thermistor portion patterned with a thermistor material on the upper surface of the insulating film, and the thin film thermistor. A pair of comb-shaped electrodes that have a plurality of comb portions on at least one of the upper and lower portions and are patterned to face each other, one end of which is connected to the pair of comb-shaped electrodes and the other end of the pair A pair of pattern electrodes connected to the lead frame and patterned on the top surface of the insulating film, the pair of lead frames and the sensor unit A pair of insulating protective tapes bonded to each other with the upper and lower sides sandwiched from each other, and both side portions of the insulating film are in the vicinity and inside of the outer corners disposed on the bonding surface side of the pair of lead frames. It is arranged, The both sides of a pair of said protective tape are bent toward the upper surface side on the outer side from the both sides of the said insulating film, It is characterized by the above-mentioned.

In the temperature sensor of the present invention, both sides of the insulating film are arranged near and inside the outer corners arranged on the bonding surface side of the pair of lead frames, and both sides of the pair of protective tape are insulated. Since the film is bent outward from both sides of the film toward the upper surface, the measurement object is hardly damaged and good responsiveness is obtained.
That is, there is a step near the outer corner due to both sides of the insulating film arranged inside the outer corner of the lead frame, and this step creates a slight gap between the protective tape and the lead frame. When the lower surface of the protective tape is brought into contact with the measurement object, the portion where the outer corner portion is arranged is difficult to hit the measurement object, and scratches are hardly generated. In addition, both sides of the protective tape are bent from the inside with respect to the outer corners of the pair of lead frames due to the narrow insulating film and the step, thereby reducing the contact surface with the measurement object and improving the response. . Furthermore, since the insulating film has a narrow width arranged on the inner side of the outer corner portion of the lead frame, the heat capacity is small and good responsiveness can be obtained. Moreover, since both sides of the protective tape are bent toward the upper surface, both sides of the protective tape do not come into contact with the measurement object, and the measurement object can be prevented from being damaged by the both sides of the protection tape.

The temperature sensor according to a second invention is the temperature sensor according to the first invention, wherein the protective tape on the upper surface side is bonded to the protective tape on the lower surface side in a state where a tensile force is applied from both side portions toward the central portion. It is characterized by being.
That is, in this temperature sensor, the upper surface side protective tape is bonded to the lower surface side protective tape with a tensile force applied from both sides to the center portion, so that the upper surface side protective tape has a tensile force. Thus, the bonded upper and lower protective tapes are bent upward on the outer sides of both sides of the insulating film, and the shape is maintained.

The temperature sensor according to a third aspect of the present invention is the temperature sensor according to the first or second aspect, wherein the distal ends of the pair of lead frames are connected to the pattern electrode at the distal end side of the thin film thermistor portion, and the proximal end It is characterized by having a shape that is wider inside than the side.
In other words, in this temperature sensor, the distal ends of the pair of lead frames are connected to the pattern electrode on the distal end side of the thin film thermistor portion, and are wider on the inside than the proximal end side. The adhesion area with the insulating film disposed on the inner side of the outer corner portion and having a smaller adhesion area can be increased with a wide tip portion, and the sensor portion can be held flat and stably. Note that the tip portion of the lead frame is arranged on the tip side of the thin film thermistor portion and is connected to the pattern electrode, so that the region of the thin film thermistor portion is not narrowed even if the tip portion is widened inward.

The present invention has the following effects.
That is, according to the temperature sensor of the present invention, the both sides of the insulating film are arranged in the vicinity and inside of the outer corners arranged on the bonding surface side of the pair of lead frames, and both sides of the pair of protective tapes. However, since it is bent toward the upper surface side from the both sides of the insulating film, the measurement object is hardly damaged and good responsiveness is obtained.
Therefore, the temperature sensor of the present invention is suitable for measuring the temperature of a heating roller of a copying machine, a printer, or the like because it can suppress damage even when pressed against an object to be measured and has high responsiveness. .

1A is a plan view showing a temperature sensor according to an embodiment of the present invention, and FIG. In this embodiment, it is a top view which shows a sensor part. In this embodiment, it is the top view (a) which shows a thin film thermistor part formation process, and the top view (b) which shows an electrode formation process. In this embodiment, it is a top view which shows a lead frame joining process. It is sectional drawing which shows the prior art example of the temperature sensor which concerns on this invention.

Hereinafter, an embodiment of the temperature sensor according to the present invention will be described with reference to FIGS. 1 to 4. Note that in some of the drawings used for the following description, the scale is appropriately changed as necessary to make each part recognizable or easily recognizable.

As shown in FIG. 1, the temperature sensor 1 according to the present embodiment includes a pair of lead frames 2, a sensor unit 3 connected to the pair of lead frames 2, and a pair of lead frames fixed to the pair of lead frames 2. And an insulating holding portion 4 that holds 2.

The sensor unit 3 includes an insulating film 5 having a pair of lead frames 2 bonded to the upper surface, a thin film thermistor unit 6 patterned with the thermistor material on the upper surface of the insulating film 5, and an upper surface of the thin film thermistor unit 6. A pair of comb-shaped electrodes 7 having a plurality of comb portions 7 a and patterned to face each other, one end connected to the pair of comb-shaped electrodes 7 and the other end connected to the pair of lead frames 2. A pair of pattern electrodes 8 patterned on the upper surface of the insulating film 5 and a pair of insulating

protective tapes

9A and 9B bonded to each other with the pair of lead frames 2 and the sensor portion 3 sandwiched from above and below are provided. ing.

Both side portions 5 a of the insulating film 5 are disposed in the vicinity and inside of the outer corner portion 2 b disposed on the bonding surface side of the pair of lead frames 2. That is, the width of the insulating film 5 is set slightly smaller than the distance between the outer corners 2 b of the pair of lead frames 2.
Further, both side portions 9a of the pair of

protective tapes

9A and 9B are bent outward from the both side portions 5a of the insulating film 5 toward the upper surface side. That is, the pair of protective tapes 9 </ b> A and 9 </ b> B is set wider than the pair of lead frames 2, and is bent in a valley fold along both side portions 5 a of the insulating film 5.
Note that the bent state is maintained by adhering the protective tape 9A on the upper surface side to the protective tape 9B on the lower surface side in a state where a pulling force is applied from both side portions toward the central portion.

The distal end portions 2a of the pair of lead frames 2 are connected to the pattern electrode 8 on the distal end side with respect to the thin film thermistor portion 6, and have a shape wider on the inside than the proximal end side.
A wide pad portion 8 a corresponding to the tip portion 2 a of the lead frame 2 is formed on the tip side of the pair of pattern electrodes 8. A pair of lead frames 2 are bonded to these pad portions 8a by an adhesive such as a solder material or a conductive resin adhesive, or resistance welding.
In the temperature sensor 1 of the present embodiment, an insulating protective film 10 that covers the pattern electrode 8, the thin film thermistor portion 6, and the comb electrode 7 excluding the pad portion 8 a is formed on the insulating film 5.

The insulating film 5 has a substantially rectangular shape, and is formed in a belt shape with a polyimide resin sheet having a thickness of 7.5 to 125 μm, for example. The insulating film 5 can be made of PET: polyethylene terephthalate, PEN: polyethylene naphthalate, or the like, but a polyimide film is desirable for measuring the temperature of the heating roller because the maximum use temperature is as high as 230 ° C.

The thin film thermistor portion 6 is disposed on the base end side of the insulating film 5 and is formed of, for example, a TiAlN thermistor material. In particular, the thin film thermistor section 6 is a metal represented by the general formula: Ti _x Al _y N _z (0.70 ≦ y / (x + y) ≦ 0.95, 0.4 ≦ z ≦ 0.5, x + y + z = 1). It consists of nitride and its crystal structure is a hexagonal wurtzite single phase.

The pattern electrode 8 and the comb-shaped electrode 7 are formed on the thin film thermistor section 6 with a thickness of 5 to 100 nm of Cr or NiCr and a noble metal such as Au on the thickness of 50 to 1000 nm. And an electrode layer formed.
The pair of comb-shaped electrodes 7 has a comb-shaped pattern in which the comb portions 7a are alternately arranged so as to face each other.

The comb portion 7 a extends along the extending direction of the insulating film 5. That is, when the back surface side of the insulating film 5 is pressed against a rotating heating roller to measure the temperature, the insulating film 5 is curved with a curvature in the extending direction of the insulating film 5. Also, bending stress is applied in the same direction. At this time, since the comb portion 7a extends in the same direction, the thin film thermistor portion 6 is reinforced, and generation of cracks can be suppressed.
The protective film 10 is an insulating resin film or the like, for example, a polyimide film having a thickness of 20 μm is employed.
The

protective tapes

9A and 9B are made of a fluorocarbon resin such as Teflon (registered trademark).
The holding portion 4 has a mounting hole 4a.

A method for manufacturing the temperature sensor 1 will be described below with reference to FIGS.
The manufacturing method of the temperature sensor 1 of the present embodiment includes a thin film thermistor portion forming step of patterning the thin film thermistor portion 6 on the surface of the insulating film 5 and a pair of comb electrodes 7 facing each other on the thin film thermistor portion 6. An electrode forming step of forming a pair of pattern electrodes 8 on the surface of the insulating film 5, a protective film forming step of forming the protective film 10 on the insulating film 5, and the lead frame 2 on the sensor unit 3. A lead frame connecting step for connecting, and a protective tape adhering step for adhering the lead frame 2 and the sensor unit 3 from above and below between the

protective tapes

9A and 9B.

As a more specific example of the manufacturing method, Ti _x Al _y is used by reactive sputtering in a nitrogen-containing atmosphere using a Ti—Al alloy sputtering target on an insulating film 5 of polyimide film having a thickness of 50 μm. A thermistor film of N _z (x = 0.09, y = 0.43, z = 0.48) is formed with a film thickness of 200 nm. The sputtering conditions at that time were an ultimate vacuum of 5 × 10 ⁻⁶ Pa, a sputtering gas pressure of 0.4 Pa, a target input power (output) of 200 W, and a nitrogen gas fraction of 20 in a mixed gas atmosphere of Ar gas + nitrogen gas. %.

A resist solution is applied onto the formed thermistor film by a spin coater, pre-baked at 110 ° C. for 1 minute 30 seconds, exposed to light with an exposure device, and unnecessary portions are removed with a developer, and further at 150 ° C. for 5 minutes. Patterning is performed by post-baking. Thereafter, the thermistor film unnecessary Ti _x Al _y N _z by wet etching in a commercial Ti etchant, as shown in FIG. 3 (a), to a thin film thermistor portion 6 of a desired shape on the resist stripping.

Next, a 20-nm-thick Cr film bonding layer is formed on the thin film thermistor portion 6 and the insulating film 5 by sputtering. Further, an Au film electrode layer is formed to a thickness of 200 nm on this bonding layer by sputtering.
Next, after applying a resist solution on the electrode layer formed by a spin coater, pre-baking is performed at 110 ° C. for 1 minute and 30 seconds, and after exposure with an exposure apparatus, unnecessary portions are removed with a developer, and at 150 ° C. Patterning is performed by post-baking for 5 minutes. Thereafter, unnecessary electrode portions are wet-etched in the order of a commercially available Au etchant and a Cr etchant, and as shown in FIG. 3B, desired comb electrodes 7 and pattern electrodes 8 are formed by resist stripping. .

Further, a polyimide varnish is applied to a predetermined portion on the surface of the insulating film 5 by a printing method and cured at 180 ° C. for 30 minutes to form a polyimide protective film 10 having a thickness of 20 μm.
Next, Ni plating is applied to a region to be the pad portion 8a, and a pair of pad portions 8a is formed as shown in FIG.
When a plurality of sensor units 3 are manufactured simultaneously, a plurality of thin film thermistor units 6, comb electrodes 7, pattern electrodes 8, protective films 10 and pad units 8a are formed on a large sheet of insulating film 5 as described above. After that, each sensor unit 3 is cut from the large sheet.
Next, as shown in FIG. 4, the tip end portion 2a of the lead frame 2 is bonded to the pair of pad portions 8a by resistance welding.

Furthermore, the sensor part 3 and the lead frame 2 are sandwiched from above and below by a pair of

protective tapes

9A and 9B, and the adhesive surfaces of the side parts 9a of the pair of

protective tapes

9A and 9B are pressed and bonded. At this time, the protective tape 9A on the upper surface side is bonded to the protective tape 9B on the lower surface side in a state where a tensile force from both side portions toward the central portion is applied. Accordingly, as shown in FIG. 1B, the lower surface side protective tape 9B is pulled inward by the upper surface side protective tape 9A, so that both side portions 9a of the pair of

protective tapes

9A and 9B are insulated. The temperature sensor 1 is manufactured by bending from both side portions 5a of the film 5 toward the upper surface side on the outside.

As described above, in the temperature sensor 1 of the present embodiment, the both side portions 5a of the insulating film 5 are disposed in the vicinity and inside of the outer corner portion 2b disposed on the bonding surface side of the pair of lead frames 2, and a pair of protections. Since both side portions 9a of the

tapes

9A and 9B are bent outward from the both side portions 5a of the insulating film 5 toward the upper surface side, the outer corner portions 2b of the lead frame 2 are difficult to come into contact with the object to be measured. Good responsiveness is obtained by the insulating film 5 having a narrow width.

That is, a step is formed in the vicinity of the outer corner 2b by both side portions 5a of the insulating film 5 disposed in the vicinity of the outer corner 2b of the lead frame 2, and the

protective tapes

9A and 9B and the lead frame are bent outside the step. When a lower surface of the protective tape 9B on the lower surface side is brought into contact with the measurement object, a portion where the outer corner portion 2b is arranged is difficult to hit the measurement object. Scratches are unlikely to occur.

Further, the both sides 9a of the

protective tapes

9A and 9B are bent from the inner side than the outer corners 2b of the pair of lead frames 2 by the narrow insulating film 5 and the step, and the contact surface with the object to be measured is small. Responsiveness is improved. Furthermore, since the insulating film 5 has a narrow width arranged on the inner side of the outer corner 2b of the lead frame 2, the heat capacity is small and good responsiveness can be obtained. In addition, since both side portions of the pair of

protective tapes

9A and 9B are bent toward the upper surface side, both side portions 9a of the pair of

protective tapes

9A and 9B do not contact the measurement object, and the pair of

protective tapes

9A and 9B It is possible to prevent the measurement object from being damaged by the side portions 9a of 9B.

Further, since the upper surface side protective tape 9A is bonded to the lower surface side protective tape 9B in a state where a tensile force is applied from both side portions 9a to the central portion, the upper surface side protective tape 9A is The upper and lower protective tapes 9 </ b> A and 9 </ b> B are bent upward on the outer sides of the both side portions 5 a of the insulating film 5, and the shape is maintained.
Further, the distal end portions 2a of the pair of lead frames 2 are connected to the pattern electrode 8 on the distal end side with respect to the thin film thermistor portion 6, and have a shape wider on the inside than the proximal end side, The sensor 3 can be held flat and stably by increasing the adhesion area with the insulating film 5 disposed on the inner side of the outer corner 2b and having a smaller adhesion area with the wide tip 5a. Note that the distal end portion 2a of the lead frame 2 is disposed on the distal end side of the thin film thermistor portion 6 and connected to the pattern electrode 8, so that the region of the thin film thermistor portion 6 is narrowed even if the distal end portion 2a is widened inward. There is nothing.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Temperature sensor, 2 ... Lead frame, 2b ... Outer corner part of lead frame, 3 ... Sensor part, 4 ... Holding part, 5 ... Insulating film, 5a ... Both sides of insulating film, 6 ... Thin film thermistor part, 7 ... Comb electrode, 7a ... Comb, 8 ... Pattern electrode, 9A, 9B ... Protection tape, 9a ... Both sides of protection tape

Claims

A pair of lead frames, a sensor unit connected to the pair of lead frames, and an insulating holding unit fixed to the pair of lead frames to hold the pair of lead frames,
The sensor part is an insulating film having the pair of lead frames bonded to the upper surface;
A thin film thermistor portion patterned with a thermistor material on the upper surface of the insulating film;
A pair of comb-shaped electrodes that have a plurality of comb portions on at least one of the upper and lower sides of the thin film thermistor portion and are patterned to face each other;
A pair of pattern electrodes having one end connected to the pair of comb-shaped electrodes and the other end connected to the pair of lead frames and patterned on the top surface of the insulating film;
A pair of insulating protective tapes bonded to each other with the pair of lead frames and the sensor unit sandwiched from above and below,
Both sides of the insulating film are arranged in the vicinity and inside of the outer corners arranged on the bonding surface side of the pair of lead frames,
A temperature sensor, wherein both sides of the pair of protective tapes are bent outward from both sides of the insulating film toward the upper surface.
The temperature sensor according to claim 1,
The temperature sensor, wherein the protective tape on the upper surface side is bonded to the protective tape on the lower surface side in a state where a tensile force from both side portions toward the central portion is applied.
The temperature sensor according to claim 1,
The distal ends of the pair of lead frames are connected to the pattern electrode on the distal end side with respect to the thin film thermistor portion, and have a shape that is wider on the inside than the proximal end side. Temperature sensor.